I have a Dunham Bush chiller M#HRSC255DQ with 4 Hitatchi screw compressors. I am having a problem with one of the compressors. The compressor will sometimes load 100% and other times it will only load up @ 50-60% even though the load solenoid has 120volts and the leaving water temp keeps rising above setpoint. The compressor continues to operate unloaded with 148 degree suction bell temp, 4 degree superheat, and the discharge line temp keeps rising tripping the compressor on high oil temp. Anyone have any ideas?